I just had this happen to my little brothers computer last night. Here is how you fix it.
1. Clear the BIOS.
2. Turn the system on.
3. AFTER 2 SECONDS PRESS CTRL THEN PAGEUP. You will hear a series of beeps.
4. Let it go for about 10 seconds.
5. Clear the BIOS again.
6. Go into the BIOS and...